The present disclosure relates generally to an apparatus and method for cooling electrical transformers, and particularly to an apparatus for controlled cooling of electrical transformers.
Electrical distribution transformers operate at a variety of kVA (kilo-Volt-Ampere) ratings, with a typical rating being 15 kVA or higher, may be dry-type or oil-filled, and may be single-phase or three-phase. Due to the electrical and magnetic characteristics of transformers, an energized transformer operating at full rated load may generate an appreciable amount of heat that needs to be dissipated. Dry-type transformers have been designed to manage this heat by sizing the electrical components for low resistance, sizing the magnetic components for low eddy current heating, and by employing a flee convection heat transfer surface to assist in heat dissipation. Oil-filled transformers have been designed to manage this heat by recirculating the oil between the coils and a heat exchanger and by employing fans or blowers to assist in cooling the oil at the heat exchanger. However, as power distribution demands increase, so does the size and cost associated with dry-type transformers, and so does the size, cost and environmental concerns associated with oil-filled transformers. Accordingly, there is a need in the art for an electrical transformer assembly that overcomes these drawbacks.